The present invention relates to hydraulic substance applied as construction material such as concrete, mortar and grout.
The hydraulic substance such as concrete, mortar and grout are produced by mixing and stiring hydraulic particles such as portland cement, fly ash and blast furnace slag particles with water, aggregate and a small amount of chemical admixture. The diameter of the hydraulic particle mentioned above is about 1.about.199 .mu.m and an average diameter thereof is about 10.about.20 .mu.m.
The mechanical properties and the durability of the hydraulic substance hardened is normally determined by the ratio of water and hydraulic particles, and the more the ratio is smaller, the more the mechanical properties and the durability thereof improve. When aggregates such as sand and stones are included in the hydraulic substance, the mechanical properties and the durability thereof after hardened are determined not only by the ratio of the water and the particles but also by a quantity of the water and the particles (the amount of the paste) and a quantity of the aggregates, and generally the ratio thereof is smaller, the more the characteristics thereof improves.
However, the more the ratio of the water and the hydraulic particles is smaller, and the more the ratio of the amount of the paste and the aggregates is smaller, the fluidity of the hydraulic substance deteriorates. Therefore, a method of improving the mechanical characteristics and the durability of the hydraulic substance by lowering the ratio of the water against the particles or lowering the ratio of an amount of the paste against the aggeregate is limited to a limiting point of the fluidity of the hydraulic substance when the fluidity required for construction is concerned.
In other words, the improvement of the quality of the hydraulic substance and the fluidity thereof are inseparably related. To resolve the problems the hydraulic substance consist of, a prior art discloses such idea that cohered cement particles, with a mixture of substance such as water-reducer, air-entraining (AE) water-reducer, high-range water-reducer, high-range AE water-reducer, are dispersed to improve the fluidity of the hydraulic substance.
Another prior art discloses such idea that fine particles more than one order smaller than hydraulic substance are dispersed evenly without a cohesion between the hydraulic particles such as cement to improve the fluidity of the hydraulic substance, and the mechanical strength and the durability thereof are also improved (Japanese Patent Publication No. 60-59182).
Further, another prior art discloses such idea that particles of cement, one of the hydraulic particles, are collided each other in a high-speed air current, removing the edges of the particles and forming thereof globular to improve the fluidity of the cement (Japanese Patent Provisional Publication No. 2-192439).
In this prior art, for the purpose of activating the reactions of the cement and of obtaining surface reactivity dissimilar to the cement, when the globular cement is to be produced in the high-speed air current, fine particles such as silica fume are applied in the high-speed air current to coat the cement with the silica fume.
In the same prior art, there are number of problems.
That is, to improve the fluidity of the hydraulic substance, applying the high-range water-reducer or the high-range AE water-reducer for dispersing the cohered hydraulic particles is considerably effective. However, to further improve the fluidity of the hydraulic substance, beside the application of the high-range water reducer, other technics are required.
The technique of evenly dispersing the fine particles, which are more than one order smaller than the hydraulic particles, without forming a cohesion between the hydraulic particles brings such effect that when the hydraulic particles deform, the shearing resistance between the particles can be reduced, but it increases the viscosity of the water between the hydraulic particles and limits the improvement of the fluidity. Further, dispersing the fine particles evenly without forming a cohesion between the hydraulic particles is extremely difficult; nearly impossible.
The technique of making globule cement is effective but it requires a high energy cost.
The globular cement coated with the fine particles is effective when the fluidity of the hydraulic substance is concerned, but it requires a cost for making up the cement globular and the cost of preparing the fine particles, which decreases the economical efficiency. Further, the cement coated with the fine particles has to keep its same condition when it is mixed with water, however, it is not clear whether or not the condition of the cement coated with the fine particles, which is performed in the high-speed air current, can be kept still the same after it is mixed with the water. It is essential that the coating of hydraulic particles by fine particles in water is assured.
Therefore, the object of the present invention is to resolve the problems the hydraulic substance has.